Go to Post Weird. On a forum where people talk about robots, we have a robot trying to talk to people. - dellagd [more]
Home
Go Back   Chief Delphi > FIRST > General Forum
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
 
 
Thread Tools Rate Thread Display Modes
Prev Previous Post   Next Post Next
  #1   Spotlight this post!  
Unread 23-08-2016, 11:26
Whatever Whatever is online now
Registered User
FRC #2502
 
Join Date: Apr 2016
Location: MN
Posts: 72
Whatever has a reputation beyond reputeWhatever has a reputation beyond reputeWhatever has a reputation beyond reputeWhatever has a reputation beyond reputeWhatever has a reputation beyond reputeWhatever has a reputation beyond reputeWhatever has a reputation beyond reputeWhatever has a reputation beyond reputeWhatever has a reputation beyond reputeWhatever has a reputation beyond reputeWhatever has a reputation beyond repute
Error bar of OPR in Stronghold

Stronghold was my first year as a mentor in FRC. I have been interested in the OPR statistic. One thing I have noticed is it commonly gets quoted to 2 decimal places which seems like way too much accuracy. So the question I have been asking myself is what is the error bar on OPR (at least for Stronghold)?


As a starting point I looked at the Einstein alliances. My thought process being those alliances have a bunch of matches together and their qual OPR would have the least oddities. I looked at division and Einstein matches where the 2nd pick of the alliance was on field and there were no red cards in the match (either side). I also assumed the alliance would breach and capture so the expected score for an alliance was the sum of the 3 OPRs plus 45.

The standard deviations of the actual scores averaged 24.6 for those alliances (min 18.2, max 34.3). The swing (max score-min score) of scores for each alliance averaged 77.9 points (min 55, max 107). 7 of the 8 alliances had an average score higher than their expected. 2 of the 8 alliances had an average score more than 30 points greater than their expected.


For a thought experiment, I created a spreadsheet that would calculate the OPRs of a small scale event. The event has 6 teams and each would play 10 matches. This meant every possible lineup is included. The match scores were the sum of 3 alliance OPRs plus a random +-25 points (roughly the average stdev of scores from the Einstein alliances). The true OPRs of the 6 teams was fixed at 60,50,40,30,20,10. After 126 events, the average OPRs for each team was under 1 away from their true OPR. The max error was just a shade over 17. Out of the 126 events, OPR had all 6 teams in the correct order 59 times. In 4 cases a team was above the team 2 places above them in true OPR.

I did sanity check the +-25 against the early week regional winning alliances. Backing out the breach/capture points, those alliances showed swings of 50 for those alliances over 6 to 8 matches. It should be noted, I used the random function in excel so the distribution of the randoms is flat and not gaussian.

So I would estimate the error bar on OPR (for Stronghold) at around 15.

Does that seem to align to other people's thoughts?
Has anyone tried to do an analysis on this?
Reply With Quote
 


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 13:23.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi